This invention relates to a new and improved apparatus used in the making of a sleeve or bladder which is used in the curing of belts and power transmission belting of the V-type.
Power transmission belts are generally made of elastomeric material containing an endless tension core which is generally formed from fabric cord and may at times be formed from stranded metal cables. In the manufacture of such power transmission belts it is essential to maintain a tensional strain on the belt during the curing process to minimize stretch when the belt is in use. The apparatus used to effect the cure of such belts includes an expandible bladder which must maintain sufficient radial pressure to effect the proper tensioning during the cure of the belt. To cure the V-belts or power transmission belting, the individual endless V-belts are stacked into a cylindrical tank or housing which will have an expandable cylindrical bladder or sleeve located radially inwardly thereof such that upon heating of the V-belts and upon pressurization of the bladder, sufficient pressure is exerted radially outwardly on the bladder to subject the V-belt to an even outward tension during cure. Steam pressure is used to cure the belts and a differential in pressure develops between the outer and inner surfaces of the bladder or sleeve such that leaks develop at the splice of the cylindrical bladder or sleeve which will ruin the production run because there is insufficient pressure exerted radially outwardly by the bladder to effect the proper tensioning of the belt for proper cure and shaping. The bladder used in such curing is essentially a cylindrical rubber sleeve which is made from a flat rectangular piece of rubber material. The respective ends of such sleeve material have been bias cut and then spliced by an overlapping tapered splice. It has been found desirable to provide an interlocking splice to make the sleeve rather than a bias or tapered splice to enhance the quality of the sleeve. Such splices extends the life of the curing bladders considerably and have eliminated costly down times for repairs.
The present invention is directed to an apparatus for efficiently cutting the interlocking cut on the respective ends of the flat sleeve material which is done on a single pass of the sleeve with a minimum of power consumption.